Pistachenoten werken
cholesterolverlagend*
Pistachenoten blijken goed te zijn voor de cholesterol volgens een kleine
Amerikaanse studie. Pistachenoten zitten boordevol bioactieve stoffen, zoals
luteïne, bètacaroteen en vitamine E in de vorm van gamma-tocoferol, die de
lichaamscellen beschermen tegen beschadiging door vrije radicalen. En de pistachenootjes bleken een
duidelijk cholesterolverlagend effect te hebben. De deelnemers aan het onderzoek
kregen drie verschillende diëten, telkens een maand lang. Het eerste dieet was een gewoon cholesterolverlagend dieet zonder noten. De andere twee diëten waren vergelijkbare diëten, waaraan
dagelijks gemiddeld 42 of 78 gram pistachenootjes werden toegevoegd. Uit de resultaten bleek dat de deelnemers veel meer
van deze bioactieve stoffen in hun bloed hadden na de diëten met pistachenootjes én dat hun cholesterol aanzienlijk lager was.
The study participants' diet began as a typical American diet of 35 percent total fat and 11 percent saturated fat for two weeks. Then, they tested three different diets for four weeks with about a two-week break between each diet.
All three of the subsequent diets were variations of the Step I Diet -- a diet meant to lower cholesterol levels. The control group diet contained no pistachios and about 25 percent total fat and 8 percent saturated fat.
The pistachio-rich diets included 10 and 20 percent of their calories supplied by the nuts. The 10 percent pistachio diet, which included 1.5 ounces of pistachios, contained 30 percent total fat and 8 percent saturated fat. The 20 percent pistachio diet, which contained 3 ounces of pistachios, contained 34 percent total fat and 8 percent saturated fat.
Both pistachio diets increased blood levels of beta-carotene, lutein and gamma-tocopherol (oil-soluble vitamins) more than the control diet. After eating both pistachio-rich diets, participants also had lower LDL levels in their blood.
Pistachios Increase Serum Antioxidants and Lower Serum Oxidized-LDL in Hypercholesterolemic Adults1,2
Colin D. Kay3,4,6, Sarah K. Gebauer3,5,7, Sheila G. West3,4 and Penny M. Kris-Etherton3,5,*
3 Department of Nutritional Sciences,; 4 Department of Biobehavioral Health, and; 5 Integrative Biosciences, The Pennsylvania State University, University Park, PA 16802
Pistachios are high in lutein, ß-carotene, and -tocopherol relative to other nuts; however, studies of the effects of pistachios on oxidative status are lacking. We conducted a randomized, crossover controlled-feeding study to evaluate 2 doses of pistachios on serum antioxidants and biomarkers of oxidative status in 28 hypercholesterolemic adults (LDL-cholesterol 2.86 mmol/L). Participants consumed 3 isoenergetic diets for 4 wk each after a 2-wk baseline Western diet. Experimental diets included a lower-fat control diet without pistachios (25% total fat) with 1 serving/d (i.e. 32-63 g/d; energy adjusted) of pistachios (1 PD; 10% energy from pistachios; 30% total fat) or with 2 servings/d (63-126g/d; energy adjusted) of pistachios (2 PD; 20% energy from pistachios; 34% total fat). When participants consumed the pistachio-enriched diets, they had higher plasma lutein (P < 0.0001), -carotene, and ß-carotene (P < 0.01) concentrations than after the baseline diet. After consuming the pistachio diets, participants had greater plasma lutein (P < 0.001) and -tocopherol (P < 0.05; 2 PD only) relative to the lower-fat control diet. After the 2 PD diet period, participants also had lower serum oxidized-LDL concentrations than following the baseline diet period (P < 0.05). After both the 1 PD and 2 PD diet periods, they had lower serum oxidized-LDL concentrations than after the control diet period (P < 0.05). The change in oxidized-LDL from baseline correlated positively with the change in LDL-cholesterol across all treatments (r = 0.42; P < 0.005). After controlling for the change in serum LDL-cholesterol as a covariate, increases in serum lutein and -tocopherol following the 2 PD period were still modestly associated with decreases in oxidized-LDL (r = -0.36, P = 0.06 and r = -0.35, P = 0.08, respectively). This suggests that a heart-healthy diet including pistachios contributes to the decrease in the serum oxidized-LDL concentration through cholesterol-lowering and may provide an added benefit as a result of the antioxidants the pistachios contain.
Journal of Nutrition, doi:10.3945/jn.109.117366
Vol. 140, No. 6, 1093-1098, June 2010 (Juni 2010)
